The present invention relates to wire bonding apparatuses and more particularly to a wire bonding apparatus that includes a pressure sensor for detecting a pressing load of a capillary.
In the apparatus of Japanese Patent Application Unexamined Publication Disclosure No. 2003-258021, as shown in FIG. 6, an ultrasonic horn 1 is held by a bonding arm 5, and a pressure sensor 10 is provided at a part where the ultrasonic horn and the bonding arm are connected. In the apparatus of U.S. Pat. No. 6,425,514, as shown in FIG. 7, a transducer (ultrasonic horn) 1 is held by a transducer holder 100 at one end of the bonding arm 5, and another end of the bonding arm 5 is secured to a bond body 104 of the bonding apparatus driven by an actuator 106. Further, a pressure sensor 10 is provided in a recess part, which is inside the horn holder 100 of the bonding arm 5, so that the pressure sensor 10 with a spring washer 102 is sandwiched by the horn holder 100 and the bond body 104.
In the apparatus of Japanese Patent Application Unexamined Publication Disclosure No. 2003-258021, as seen from FIG. 6, the pressure sensor 10 is provided at a part where the ultrasonic horn 1 and the bonding arm 5 are connected. Accordingly, when replacing the ultrasonic horn 1, the pressure sensor 10 must also be removed from the bonding arm 5. For this reason, every time the ultrasonic horn is replaced, disassembly, reassembly, and load calibration of the pressure sensor are required. Thus, working performance is poor.
Moreover, in both apparatuses of Japanese Patent Application Unexamined Publication Disclosure No. 2003-258021 and U.S. Pat. No. 6,425,514, the position where the pressure sensor is provided is limited because the pressure sensor is provided between component parts that have different functions. Accordingly, there is little mechanism design freedom, and the magnification factor for the capillary pressing load detected by the pressure sensor is limited.